Toyota, Lexus and recently even Kia have been talking about their self charging hybrids -and how they are an advantage because they don’t need plugging in.
Obviously they are not travelling for free, so where is this energy gained from and how far can it carry you?
Internal-combustion cars are some of the most inefficient converters of energy to movement. The majority of combustion engine cars have an efficiency under ⅓. self-charging hybrids, charge up small battery during braking and in all the moments when it can regain some of the energy. In other words, in a self-charging hybrid you are exchanging a plug socket for a petrol pump. Given the charging a fully electric car even at an expensive place doesn’t usually exceed £20, yet filling up a petrol car can easily run to £60 – from a financial point of view this exchange is stupid.
Self-charging hybrids, are essentially more efficient combustion engine cars. In normal operation some of the power that you lose is put into the battery to accelerate you again. However given that self-charging hybrids, often have batteries that are well under 10 kilowatt-hours, you will not be able to drive them for more than a few miles in pure electric fashion.
A recent new model that could fall under this badge is the new London taxi. However, as this taxi has a battery of about 30 kilowatt hours, so with its fuel tank this range is extended to about 300 miles. Assuming however that the taxi is being driven mostly on short routes, and that the taxi driver can find a fast charger to fill it back up, a battery of this size could allow the taxi to run as a fully electric taxi (certainly it would be possible for it to operate as fully electric for a significant part of its life – say over 50%).
Generally a self-charging hybrid has a much smaller battery than this, allowing you to do very short trips-only a matter of a few miles, before the combustion engine kicks in. As a result of this “self-charging hybrids” are generally combustion engine cars which can do do trips about town on electric power.
Because of the way that these are set up, while they improve the efficiency of cars, they aren’t really much of a step forwards. Far from it, as they have to have both the ability to run on electricity and fossil fuels these cars are more complicated. People buy these cars will continue to have to use fossil fuels for the life cycle of their car.
The cheapest “self-charging hybrid” generally costs a little over £20,000. However to buy a half decent sized family car of this persuasion will require at least £30,000. Given that these cars are run mostly on fossil fuels, owners are likely to still be spending several thousand pounds a year, on petrol or diesel. The Tesla model 3 starts at around £40,000, but if charged at home can save more than 80% of the money you spend at petrol stations.
This means that if you buy a large self charging hybrid,you can easily spend more over the life cycle of the car than you would have done on a fully electric car – and the carbon emissions you have released will be barely lower then they would have been if you went for other car.
Basically these are bad for the climate and bad for your wallet, even if marginally better than a pure combustion engine car. You are far better off borrowing a small amount more, and buying a pure electric car.